Sulphur mineralization kinetics of cattle manure and green waste compost in soils.

Sulphur mineralization of cattle manure (CM) and green waste compost (GWC) added to six agricultural soils with different chemical properties was monitored over 10 weeks in a laboratory incubation experiment. Although the amount of sulphur was higher in CM than in GWC, the cumulative SO4(2-)-S values in GWC-treated soils were higher than in soil amended with CM. The percentages of mineralized S were always higher in GWC-treated soil (in the range 1.3-8.5%) than in CM-treated soil (in the range 0.9-3.8%). In three of the six soils, particularly for CM, an immobilization of sulphur was observed. Three kinetic models were evaluated for their suitability to describe the mineralization process. The first-order model best described S mineralization for both amended and control soils. The GWC substantially increased the amount of potentially mineralizable S (S0) relative to the controls. In GWC-treated soils, the rates of S mineralization (k) were higher than rates in the controls. The k of CM-amended soils was often lower than the k of control soils. Parameters derived from the model were tested as indices for assessing the relationships between S mineralization and soil characteristics. The S0 was positively correlated to the amount of cumulative SO4(2-)-S and also to the content of organic C, N and S in soil.     

Trace elements in compost regulation: the case of Spain

We use the example of the Spanish Decree on Fertilizers (2005) to discuss the need of new horizontal regulations for assessing the quality of all the materials reaching the soil as amendments of fertilizers, in particular in what concerns potentially toxic trace elements in compost. Here it is proposed that the new regulations take into account the following: establishing maximum legal limits for the total loads for each element when compost is added to agricultural soils; establishing the maximum total concentration and bioavailability of each element in the final compost; and that they take into account the soil characteristics for establishing those limits.     

Integrated geophysical surveys on waste dumps: evaluation of physical parameters to characterize an urban waste dump (four case studies in Italy).

Geophysical surveys were carried out on different waste dumps to evaluate key geometric and physical parameters. Depending on the dump dimensions and physical characteristics different geophysical techniques were used. Vertical electrical sounding, electrical resistivity tomography, induced polarization and seismic refraction techniques were integrated to eliminate the non-uniqueness of solutions and for a better understanding of the results. Physical parameters inside and outside the dumps were compared. The change of physical parameters such as resistivity, chargeability, and P-wave velocity allowed evaluation of waste dump geometry, leachate saturation levels, and thickness of waste. Furthermore, in illegal dumps, the size and waste type disposed could be evaluated. Calculated results were compared with plans and book-keeping from the dumps investigated.     

Microbiological assessments of compost toilets: in situ measurements and laboratory studies on the survival of fecal microbial indicators using sentinel chambers

Compost toilet systems were assessed for their ability to reduce microbial indicators and pathogens. Bacterial pathogens were not detected in any samples indicating a low survival rate in composting feces and/or an initial low occurrence. Indicator bacteria showed large variations with no clear trend of lower bacterial numbers after longer storage. In controlled composting experiments, thermophilic conditions were only reached when amendments were made (grass and a sugar solution). Even then it was impossible to ensure a homogenous temperature in the composting fecal material and therefore difficult to achieve a uniform reduction and killing of indicator organisms. Presumptive thermotolerant coliforms, Salmonella typhimurium Phage 28 B and eggs of Ascaridia galli, proved useful as indicators. However, regrowth was detected for enterococci and total numbers of bacteria grown at 36 degrees C. These indicator parameters may therefore overestimate the level of other (pathogenic) bacteria present in the material and can not be recommended for use as reliable indicator organisms in composting toilet systems. The addition of indicator bacteria to fecal material contained in semi-permeable capsules proved to be a useful technique to ensure that microorganisms were contained in a small test volume.     

Development of a model for the evaluation of compost supply–demand dynamics: theory and case study in an area of Rabat region,Morocco

Journal of Material Cycles and Waste Management - Compost Supply–Demand (CSD) dynamics is one of the important aspects to consider when assessing composting plants’ sustainability....     

Status and challenges of hospital solid waste management: case studies from Thailand, Pakistan, and Mongolia

Healthcare waste management is a serious public health concern. In developing countries, compared to developed nations, the management of infectious wastes has not received sufficient attention. Recently, worldwide awareness has grown of the need to impose stricter controls on the handling and disposal of wastes generated by healthcare facilities. This exploratory study attempted in seven selected hospitals to explain the situation of healthcare waste management, with a focus on handling practices, occupational safety, and the implementation status of waste management policy, together with other pertinent policy issues. It was noted that the current system of healthcare waste management was underdeveloped and was in dire need of immediate attention and improvement, especially in Mongolia and Pakistan; the medical waste management practices were better in the hospitals studied in Thailand. This study underscores the importance for improvement of medical waste management of a national regulatory framework, a sound internal management system, and programs to train and ensure the safety of related personnel, as well as programs to estimate quantities of waste generated and to evaluate appropriate techniques of disposal. Once a healthcare waste management plan has been prepared, a regular program of inspection and review can be undertaken within the healthcare institution. A good inspection program can also expose problems and new issues in managing healthcare wastes.     

Participatory approach, acceptability and transparency of waste management LCAs: case studies of Torino and Cuneo

The paper summarises the main results obtained from two extensive applications of Life Cycle Assessment (LCA) to the integrated municipal solid waste management systems of Torino and Cuneo Districts in northern Italy. Scenarios with substantial differences in terms of amount of waste, percentage of separate collection and options for the disposal of residual waste are used to discuss the credibility and acceptability of the LCA results, which are adversely affected by the large influence of methodological assumptions and the local socio-economic constraints. The use of site-specific data on full scale waste treatment facilities and the adoption of a participatory approach for the definition of the most sensible LCA assumptions are used to assist local public administrators and stakeholders showing them that LCA can be operational to waste management at local scale.     

Induction of enhanced methane oxidation in compost: temperature and moisture response

Landfilling is one of the most common ways of municipal solid waste disposal. Degradation of organic waste produces CH(4) and other landfill gases that significantly contribute to global warming. However, before entering the atmosphere, part of the produced CH(4) can be oxidised while passing through the landfill cover. In the present study, the oxidation rate of CH(4) was studied with various types of compost as possible landfill cover. The influence of incubation time, moisture content and temperature on the CH(4) oxidation capacity of different types of compost was examined. It was observed that the influence of moisture content and temperature on methane oxidation is time-dependent. Maximum oxidation rates were observed at moisture contents ranging from 45% to 110% (dry weight basis), while the optimum temperature ranged from 15 to 30 degrees C.     

Phytoremediation of landfill leachate and compost wastewater by irrigation of Populus and Salix: Biomass and growth response

A pot experiment is described with a fast-growing poplar clone and two native willows (Populus deltoides Bartr. cl. I-69/55 (Lux)), Salix viminalis L. and Salix purpurea L.), irrigated with landfill leachate and compost wastewater over a 1-year growing period. The use of leachate resulted in up to 155% increased aboveground biomass compared to control water treatments and in up to 28% reduced aboveground biomass compared to a complete nutrient solution. The use of compost wastewater resulted in up to 62% reduced aboveground biomass compared to the control treatments and in up to 86% reduced aboveground biomass compared to the complete nutrient solution. Populus was the most effective in biomass production due to the highest leaf production, whereas S. purpurea was the least effective in biomass accumulation, but less sensitive to high ionic strength of the irrigation water compared to S. viminalis. The results showed a high potential for landfill leachate application (with up to 2144 kg N ha^?1, 144 kg P ha^?1, 709 kg K ha^?1, 1010 kg Cl ha^?1, and 1678 kg Na ha^?1 average mass load in the experiment). High-strength compost wastewater demonstrated less potential for application as irrigation and fertilization source even in high water-diluted treatments (1:8 by volume).     

Utilization of turkey manure as granular activated carbon: physical, chemical and adsorptive properties

The high availability of large quantities of turkey manure generated from turkey production makes it an attractive feedstock for carbon production. Pelletized samples of turkey litter and cake were converted to granular activated carbons (GACs) by steam activation. Water flow rate and activation time were changed to produce a range of activation conditions. The GACs were characterized for select physical (yield, surface area, bulk density, attrition), chemical (pH, surface charge) and adsorptive properties (copper ion uptake). Carbon physical and adsorptive properties were dependent on activation time and quantity of steam used as activant. Yields varied from 23% to 37%, surface area varied from 248 to 472 m(2)/g and copper ion adsorption varied from 0.72 to 1.86 mmol Cu(2+)/g carbon. Copper ion adsorption greatly exceeded the values for two commercial GACs. GACs from turkey litter and cake show considerable potential to remove metal ions from water.     

Economical and environmental implications of solid waste compost applications to agricultural fields in Punjab,Pakistan

Application of municipal solid waste compost (MSWC) to agricultural soils is becoming an increasingly important global practice to enhance and sustain soil organic matter (SOM) and fertility levels. Potential risks associated with heavy metals and phosphorus accumulations in surface soils may be minimized with integrated nutrient management strategies that utilize MSWC together with mineral fertilizers. To explore the economic feasibility of MSWC applications, nutrient management plans were developed for rice–wheat and cotton–wheat cropping systems within the Punjab region of Pakistan. Three-year field trials were conducted to measure yields and to determine the economic benefits using three management strategies and two nutrient doses. Management strategies included the application of mineral fertilizers as the sole nutrient source and application of mineral fertilizers in combination with MSWC with and without pesticide/herbicide treatments. Fertilizer doses were either based on standard N, P and K recommendations or on measured site-specific soil plant available phosphorus (PAP) levels. It was found that combining MSWC and mineral fertilizer applications based on site-specific PAP levels with the use of pesticides and herbicides is an economically and environmentally viable management strategy. Results show that incorporation of MSWC improved soil physical properties such as bulk density and penetration resistance. The PAP levels in the surface layer increased by the end of the trials relative to the initial status. No potential risks of heavy metal (Zn, Cd, Cr, Pb and Ni) accumulation were observed. Treatments comprised of MSWC and mineral fertilizer adjusted to site-specific PAP levels and with common pest management showed highest cumulative yields. A basic economic analysis revealed a significantly higher cumulative net profit and value-to-cost ratio (VCR) for all site-specific doses.     

Bioconversion of dairy manure by black soldier fly (Diptera: Stratiomyidae) for biodiesel and sugar production

Modern dairies cause the accumulation of considerable quantity of dairy manure which is a potential hazard to the environment. Dairy manure can also act as a principal larval resource for many insects such as the black soldier fly, Hermetia illucens. The black soldier fly larvae (BSFL) are considered as a new biotechnology to convert dairy manure into biodiesel and sugar. BSFL are a common colonizer of large variety of decomposing organic material in temperate and tropical areas. Adults do not need to be fed, except to take water, and acquired enough nutrition during larval development for reproduction. Dairy manure treated by BSFL is an economical way in animal facilities. Grease could be extracted from BSFL by petroleum ether, and then be treated with a two-step method to produce biodiesel. The digested dairy manure was hydrolyzed into sugar. In this study, approximately 1248.6 g fresh dairy manure was converted into 273.4 g dry residue by 1200 BSFL in 21 days. Approximately 15.8 g of biodiesel was gained from 70.8 g dry BSFL, and 96.2 g sugar was obtained from the digested dairy manure. The residual dry BSFL after grease extraction can be used as protein feedstuff.     

Landfill leachate assessment by hydrological and geophysical data: case study NamSon,Hanoi, Vietnam

The main objective of this study was to assess the impact of the NamSon landfill on subsurface geological structure and hydrological environment by geophysical techniques and hydrochemical analysis of surface and groundwater. The electrical resistivity tomography (ERT), self-potential (SP) and very low frequency (VLF) methods were used for the investigation of geological structure near the landfill. Three profiles (900 m long in total) of the two-dimensional ERT, VLF density sections and 180 SP data points scattered throughout the study area near the disposal site constituted the basis of the data used in analysis. Additionally, surface water and groundwater samples were collected from six sites in the area for the chemical analysis. Interpretations of geophysical data show a low resistivity zone (< 15 Ωm), which appears to be a fully saturated zone with leachate from landfill. The results of the geophysical investigations are not always fully confirmed by the results of hydrochemical analysis. The quality of water in the vicinity of the landfill dramatically decreased over the year (2015–2016) and actions should be taken to inverse this negative trend.

     

Empirical analysis of reward to return: based on case studies of lunch boxes in Japan

To recycle or reuse used containers, it is necessary first to collect them. One way to do this is to give rewards to persons who return used packaging and containers to designated places. Many Japanese university cooperatives use recyclable lunch boxes for take-out food, and they collect used boxes in a variety of ways, including such reward giving. By analyzing the responses of university cooperatives to questionnaires on the ways that they collect used recyclable lunch boxes, this study examines the effect of this reward giving on the collection rate. The study results suggest that cash rewards are more effective in increasing the rate of return of used containers than setting up collection boxes that offer no rewards upon return, or giving point-based rewards.     

Recycling of organic wastes in burnt soils: combined application of poultry manure and plant cultivation

A pot experiment was conducted to investigate the efficacy of a post-fire land management practice, including plant cultivation (Lolium perenne) combined with poultry manure addition, for restoring the protective vegetation cover in soils degraded by high intensity wildfires. The greenhouse experiment was performed with three burnt pine forest soils with added poultry manure at two doses of application and comparing the data with those obtained using NPK fertilizer. A significant effect of the amendment, soil properties and the interaction between amendment and soil properties on vegetation cover (phytomass production, nutrient content) was detected, but often the amendment treatment explained most of the variance. Changes induced by the organic amendment were more marked than those induced by inorganic fertilization. The increase of phytomass and nutrient uptake with poultry manure addition indicated the beneficial effects of this soil management practice. These findings can serve to develop field experiments and burnt soils reclamation technology.     

Application of compost of two-phase olive mill waste on olive grove: Effects on soil,olive fruit and olive oil quality

Composting is a method for preparing organic fertilizers that represents a suitable management option for the recycling of two-phase olive mill waste (TPOMW) in agriculture. Four different composts were prepared by mixing TPOMW with different agro-industrial by-products (olive pruning, sheep manure and horse manure), which were used either as bulking agents or as N sources. The mature composts were added during six consecutive years to a typical “Picual” olive tree grove in the Jaén province (Spain). The effects of compost addition on soil characteristics, crop yield and nutritional status and also the quality of the olive oil were evaluated at the end of the experiment and compared to a control treated only with mineral fertilization. The most important effects on soil characteristics included a significant increase in the availability of N, P, K and an increase of soil organic matter content. The application of TPOMW compost produced a significant increase in olive oil content in the fruit. The compost amended plots had a 15% higher olive oil content than those treatment with inorganic fertilization. These organics amendments maintained the composition and quality of the olive oil.     

Intelligent bio-conversion of food waste by housefly larvae: a small-scale case in Nanjing,China

Journal of Material Cycles and Waste Management - This NOTE summarizes process, practical case, and perspectives of intelligent bioconversion via insect (housefly larvae) for treating food waste...     

Structure of chemical components in different compost extracts characterized by chromatogram and spectroscopy analysis and its influence on plant growth promotion

Pig manure rice straw compost was extracted using different extraction methods, and the composition of each extraction was identified by chromatogram and spectroscopy in order to investigate plant growth promoting factors. Compared with direct extraction, aerated and non-aerated fermentation extractions were better for nutrient accumulation, especially for high molecular weight substances. Cucumber yields of aerated fermentation extraction of compost (AFEC) treatment were 16.5 and 57.6?% higher than the direct extraction of compost (DEC) and non-aerated fermentation extraction of compost (NAFEC) treatments. Humic acid-like and fulvic acid-like substances were the main components in all extracts. Furthermore, AFEC showed the most humification and aromatization. Humic substances extracted from AFEC (H-AFEC) increased shoot dry weight by 2.8 and 7.4?%, compared to humic substances extracted from DEC (H-DEC) and humic substances extracted from NAFEC (H-NAFEC). In conclusion, AFEC was the best extraction method to get more humic substances to stimulate plant growth.     

Difficulties in applying extended producer responsibility policies in developing countries: case studies in e-waste recycling in China and Thailand

Developing Asian countries have started to apply the principle of extended producer responsibility (EPR) to electronics and electrical equipment waste (e-waste). This policy approach aims to give electronic appliance manufacturers and importers responsibility for the collection and recycling of discarded electronic equipment. China and Thailand have drafted regulations on the recycling of e-waste with common characteristics such as the financial responsibility of producers and subsidies for collection. Although the proposed system is sensible, taking into account the fact that e-waste is a market-traded commodity, there are two major difficulties in implementing EPR in developing countries. First, it may be difficult for governments to collect funds from producers or importers if smuggled, imitation, or small shop-assembled products have a large share in the market. Second, the system creates incentives for collectors and recyclers to over-report the amount of collected e-waste in order to gain extra subsidies from the fund. Other policy measures such as the enforcement of pollution control regulations on informal recyclers, the prevention of smuggling, and the protection of intellectual property rights should accompany EPR policies.